Bridge-dam.



H. L. OOBURN.

, BRIDGE DAM. I APPLICATION PILED MAY 1,1908.

rammed 0013.6,1908.

from, the passageway Y invention, portions of the body portion be nowiso LJco an, or nos'ron, MASSAUHUSETES.

' anon-near.

No, 900,354 Specification of Letters Patent.

Patented that. 8. 1908.

Application flied may 1, 19%. Serial bio. 430,273.

tion and b c the end portions of a dam embodying my invention. The end ortions b c are or may be the usual bulkhea' .s which are higher than the body of water impounded by the dam, and constitute the Limits of the sheet of water which flows over the body portion a, the latter bein constructed to uide the overfall between t e end portions ii 0.

; The body portion a is formed to cover and dbed d which may be of protect a way or roa any suitable character, and 15 here shown as To all whom it may concern:

Be it known that I, HowARn' L. Comma, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Bridge-Dams, of which the f llowing is a specification. This invention relates to a dam of such construction as to provide a passageway across the river or stream under the water which flows over the dam, so that the body of the damover which the overfall passes,

constitutes abridge or passageway on or the supporting the rails e e of a railroad track. overfall. which may be of standard gage. Fhe body The invention has for its object to provide a dam of this character, the end ortions or bulkheads of which are so located relatively to the intermediate portion or body of the dam as to provide approaches to, and exits substantiall in line with said way so that a railway trac may be extended through the body of the dam and throu h areas rotected by the end portions or bul dreads, t to entire ortion of the track, included in the bod of die dam and the said areas, being straig t or free from abrupt curves. I i

The invention consists in a dam compria" ing a body portion, over which the overflow from the impounded water passes, said body portion forming a passageway under the overi'all, and bulkheads or confining structures at the ends of the body portion, said confining end structures being offset upstream i'rom the body portion, so that areas are formed at the downstream sides of the and structures in alinement with the passage through the body of the dam, thus permitting a substantially straight railway track or other roadway to extend through said body portion and the said areas all as hereinafter more fully described.

Oi the accompanying part of this specification, a perspective view portion a as here shown, comprises a deck 2 at the upstream side of the dam, and an apron 3 at the downstream side, said parts being connected by a crest 4, the whole construction being preferably of reinforced concrete, and including buttresses openings 6 are formed above the roadbed d.

The end ortion t is here shown as a head, whic is built higher than the crest 4, and forms a suitable water confining connection between one end of the dam body a, and the corresponding bank oi the stream or river. The end portion a is here shown as a part of a power house built at stream and constructed to serve the same function as the bulkhead b. if desired, the end portion 0, instead of being a part of a ower house, Ina be a bulkhead oi' the same construction as t e part b.

In carrying out my 'nvention, i offset the end portions or structures b c toward the up stream side of the dam, thereby providing open areas at opposite ends of the ody portion a, and in ahnement therewith, so that a railway track or other way, extendin through the body portion a, may be extends in a substantially straight line to any desired e rtent from the opposite cm s of the body portion. Provision is thus made for utilizing a hollow or shell dam as the cover of a railway bridge or other highway, proaches to, and exits from, the passageway through the body portion being unobstructed.

I do not limit myseli to the construction of the darn body and the end structures here shown and described,.as any other suitable drawing forming a Figure 1 represents of a dam embody ng my ing broken away to show the interior. Fig. 2 is a section on line 2-2 of-Fig. 1. i

The same letters of reference indicate the some parts in. all the figures.

in the drawings, a represen s the body per 5 in. which.

bulkthe apeemi-rueticn may be adapted whmeby the bjsut of my inven' aimx is mmiw 3Q tslaairh:- A dam compririing :2 b0

00d portion fuming a pmsng the oven-{all and Wa-Lerwedinin s 5:71 the ands of the. body I 1. mid m with said passageway.

In tcshn'xony whi-Tenf 1 have fir: signature, in presence of two \vifincw HOWARD L. COBUHN. "Witnesses:

S. E. ROCKWELL, l'iomwu S. BABSET. 

